Is Branch County, MI a radon risk area?

EPA's own radon map rates Branch County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Rank it against the rest of the country and Branch County lands in the 89th percentile for radon potential.

Branch County by the numbers

About 46,187 people live in Branch County, Michigan, spread over 506.411 square miles. That works out to roughly 91 people per square mile. Rank 336 by population within its EPA zone puts Branch County at the 69th percentile among zone peers. EPA's geology-based Region 5 groups Branch County with 523 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Branch County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. EPA's guidance doesn't change because of a Zone 1 label: test the house. What changes is the reason to not put it off in Branch County specifically.

If Branch County tests above the action level

Nothing about Branch County's EPA zone changes the mitigation number: $800–$2,500 nationally (around $1,200 typical), set by the house's foundation rather than the county it sits in — and only relevant once a test actually clears 4 pCi/L.

Find Michigan's state radon program

Branch County's test kit answers today; a Airthings radon monitor keeps answering for Branch County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

More on how this number was built

Branch County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.